It is known in the art that the concomitant use of a hindered amine light stabilizer with a UV-absorber such as a 2H-benzotriazole provides excellent stabilization in many polymer compositions as summarized by G. Berner and M. Rembold, "New Light Stabilizers for High-Solids Coatings", Organic Coatings Science and Technology, Vol 6, Dekkar, New York, 1984, pp 55-85.
Molecules containing both a UV-absorber moiety and a hindered amine moiety with an N-H, N-alkyl or N-alkanoyl group are described in U.S. Pat. Nos. 4,344,876; 4,426,471; 4,314,933; and 4,619,956; British Patent Application 2,188,631; and L. Awar, et al, "New Anti-UV Stablizers for Automotive Coatings" (Presented at 1988 Annual Meeting of Federation of Societies for Coatings Technology).
The concomitant use of a separate hindered amine molecule and a separate UV-absorber molecule is also taught in U.S. Pat. No. 4,619,956.
N-Hydrocarbyloxy derivatives of hindered amine light stabilizers are less basic than the corresponding N-H or N-alkyl derivatives. As such, the N-hydrocarbyloxy derivatives offer an important advantage in polymer systems where the basicity of hindered amines generally causes undesired interactions with the polymer system such as cure retardation in high solids thermoset acrylic automotive coatings.
The instant N-hydrocarbyloxy derivatives being less basic do not cause cure retardation in such polymer systems.